Gnome keyring and KDE KWallet are essentially the same thing (if you are familiar with KDE).

Judging by the message my guess is it can not place the passwords in memory in whatever it defines as a 'secure' place that can't be read or corrupted by other programs.

If it's stored on disk instead of in memory, hopeflly not in $TMPDIR, /tmp, /var/tmp. And stored with a decent encryption algorithm so that access is done by prompting the daemon for it's unencrypted form.

Be worried? Depends on the situation.

The first virtual teletype is a place where a number of system messages go, you can adjust whats sent there with syslog's facilities for it I think.

its not running as root. you could make the program suid but IMO making a program suid thats not been carefully written and audited is a greater risk than someone reading sensitive info paged out to disk.
i would suggest that you ignore the error messages and if it bugs you too much you could disable it via syslog.conf. if you still have any doubts then write to the port maintainer.